16561548585936 has 320 divisors, whose sum is σ = 48255014536960. Its totient is φ = 5437835182080.

The previous prime is 16561548585893. The next prime is 16561548585937. The reversal of 16561548585936 is 63958584516561.

16561548585936 is a `hidden beast` number, since 1 + 6 + 5 + 6 + 1 + 5 + 4 + 8 + 585 + 9 + 36 = 666.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16561548585937) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 10179193155 + ... + 10179194781.

It is an arithmetic number, because the mean of its divisors is an integer number (150796920428).

Almost surely, 2^{16561548585936} is an apocalyptic number.

16561548585936 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 16561548585936, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24127507268480).

16561548585936 is an abundant number, since it is smaller than the sum of its proper divisors (31693465951024).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

16561548585936 is a wasteful number, since it uses less digits than its factorization.

16561548585936 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2739 (or 2727 counting only the distinct ones).

The product of its digits is 933120000, while the sum is 72.

The spelling of 16561548585936 in words is "sixteen trillion, five hundred sixty-one billion, five hundred forty-eight million, five hundred eighty-five thousand, nine hundred thirty-six".